The Bill O'Reilly-Jon Stewart 'rumble': More than a jab-fest?

In the left corner, comedian Jon Stewart. In the right corner, Fox News shout-meister Bill O'Reilly. What might they achieve, besides self-promotion, when they face off Saturday night for a political debate?

Half the proceeds from the "debate" will go to charities, but let's be honest here. The rumble serves as a giant promotion to attract more followers to “The Daily Show with Jon Stewart” on Comedy Central and “The O’Reilly Factor” on Fox News.